1. Field of the Invention
This invention concerns itself with light sensitive separators that distinguish different materials based on their reflected light. In particular, our invention takes a concentrate that has been subjected to a prior primary separating step and further monitors its reflected light to insure a final separation.
2. Description of the Prior Art
Light sensitive cells like photocells have long been used to detect the color of mineral products moving on a surface and to use the detected color to control the actuation of some type of sorting device. The 1928 U.S. Pat. No. 1,678,884 to A. T. Sweet discloses an ore separation device which is based on the color of light reflected from the materials. It also employs a stationary photocell and light source over a moving surface that carries the ore that is being separated. However, the ore is segregated solely on the color characteristics of the reflected light which could mean two rocks of different ore but closely resembling each other in color would be grouped together. Our invention overcomes this apparent type of possible error based solely on the detected color, by combining a mobile photocell detector and separator with a primary separator which has previous separated and concentrated material according to its make-up. This gives a degree of concentration of the recovered material heretofore available on such a scale.